NWS issues warning for severe storm potential this weekend

Editor’s Note: Weather reports can vary widely in as little as six hours. However, we are issuing this report due to the National Weather Service’s warnings as to the potentially dangerous nature of the weather being forecast and with a desire to give our readers the most time possible to be prepared for severe weather, should it occur.

Tuesday morning, the National Weather Service office in Johnston began warning of possible severe storms this weekend in its long-term forecast. This morning, forecasters posted a “potential severe weather” alert on their website.

“After an uneventful frontal passage today, a strong area of low pressure will lift out of the Southwestern U.S. and into the Central Plains Friday night through Saturday night,” the alert stated. “This system has the potential to bring strong to severe weather to Iowa beginning late Friday night through Saturday evening. A few tornadoes are even possible. Heavy rainfall is also possible with some of these storms.”

The National Storm Prediction Center in Norman, Okla., has issued a similar warning, placing the entire state of Iowa in a cone of high probability for severe weather beginning late Friday night and throughout the day Saturday. As of this morning, the Johnston office was forecasting the worst of the storm to strike central Iowa during the afternoon hours.

There is a small chance, however, that conditions that would lead to severe weather may not develop. But forecasters in Johnston have discounted those chances, and are urging citizens to stay abreast of weather conditions throughout the weekend.

The Iowa Storm Chasing Network, a group of meteorologists studying severe weather in and around Iowa, has similarly issued warnings about the potential for severe weather. Nick Weig, who heads the research group, has witnessed some of the most damaging storms in recent history, including the EF5 tornado that struck Parkersburg in 2008.

“Right up to the morning of this potential severe weather outbreak, conditions will not feel like storms are on the way,” he said. “Temperatures will remain cool across the region. But on Saturday morning, it’s expected that a powerful warm front will push through, bringing a sudden and brief warm up that could send temperatures back into the 70s across the state.”

Weig said this is all that is needed to trigger strong to severe thunderstorms. He said with the right conditions — and this system has high degree of potential to create them — “all modes of severe weather are possible Saturday afternoon and evening across the state.”

“Besides tornado, the other large threat from this storm system will be a widespread wind event,” he said. “The National Weather Service in Des Moines likened this setup to another recent event: the severe weather outbreak in central Iowa back on Nov. 12, 2005. That outbreak produced tornadoes in the Ames area that caused significant damage.”

Weig stressed the biggest danger from a late-season storm is ignorance, particularly with so many communities beginning to focus on preparations for snow and ice.

“Tack on the fact this comes during a weekend and you’ve got a severe recipe for disaster,” he added. “I cannot stress this point enough: if you have any plans this weekend, or if you know someone who does, please make sure they are aware of the impending situation and take the necessary steps to prepare or to at least stay informed as this situation develops.”

Bob Eschliman is editor of the Daily News. He can be contacted at (641) 792-3121, ext. 423, or at beschliman@newtondailynews.com.